freebsd-dev/sys/dev/iicbus/lm75.c

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/*-
* Copyright (c) 2010 Andreas Tobler.
* Copyright (c) 2013-2014 Luiz Otavio O Souza <loos@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_platform.h"
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/endian.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <machine/bus.h>
#include <dev/iicbus/iicbus.h>
#include <dev/iicbus/iiconf.h>
#ifdef FDT
#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#endif
/* LM75 registers. */
#define LM75_TEMP 0x0
#define LM75_TEMP_MASK 0xff80
#define LM75A_TEMP_MASK 0xffe0
#define LM75_CONF 0x1
#define LM75_CONF_FSHIFT 3
#define LM75_CONF_FAULT 0x18
#define LM75_CONF_POL 0x04
#define LM75_CONF_MODE 0x02
#define LM75_CONF_SHUTD 0x01
#define LM75_CONF_MASK 0x1f
#define LM75_THYST 0x2
#define LM75_TOS 0x3
/* LM75 constants. */
#define LM75_TEST_PATTERN 0xa
#define LM75_MIN_TEMP -55
#define LM75_MAX_TEMP 125
#define LM75_0500C 0x80
#define LM75_0250C 0x40
#define LM75_0125C 0x20
#define LM75_MSB 0x8000
#define LM75_NEG_BIT LM75_MSB
#define TZ_ZEROC 2731
/* LM75 supported models. */
#define HWTYPE_LM75 1
#define HWTYPE_LM75A 2
/* Regular bus attachment functions */
static int lm75_probe(device_t);
static int lm75_attach(device_t);
struct lm75_softc {
device_t sc_dev;
struct intr_config_hook enum_hook;
int32_t sc_hwtype;
uint32_t sc_addr;
uint32_t sc_conf;
};
/* Utility functions */
static int lm75_conf_read(struct lm75_softc *);
static int lm75_conf_write(struct lm75_softc *);
static int lm75_temp_read(struct lm75_softc *, uint8_t, int *);
static int lm75_temp_write(struct lm75_softc *, uint8_t, int);
static void lm75_start(void *);
static int lm75_read(device_t, uint32_t, uint8_t, uint8_t *, size_t);
static int lm75_write(device_t, uint32_t, uint8_t *, size_t);
static int lm75_str_mode(char *);
static int lm75_str_pol(char *);
static int lm75_temp_sysctl(SYSCTL_HANDLER_ARGS);
static int lm75_faults_sysctl(SYSCTL_HANDLER_ARGS);
static int lm75_mode_sysctl(SYSCTL_HANDLER_ARGS);
static int lm75_pol_sysctl(SYSCTL_HANDLER_ARGS);
static int lm75_shutdown_sysctl(SYSCTL_HANDLER_ARGS);
static device_method_t lm75_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, lm75_probe),
DEVMETHOD(device_attach, lm75_attach),
DEVMETHOD_END
};
static driver_t lm75_driver = {
"lm75",
lm75_methods,
sizeof(struct lm75_softc)
};
static devclass_t lm75_devclass;
DRIVER_MODULE(lm75, iicbus, lm75_driver, lm75_devclass, 0, 0);
static int
lm75_read(device_t dev, uint32_t addr, uint8_t reg, uint8_t *data, size_t len)
{
struct iic_msg msg[2] = {
{ addr, IIC_M_WR | IIC_M_NOSTOP, 1, &reg },
{ addr, IIC_M_RD, len, data },
};
if (iicbus_transfer(dev, msg, nitems(msg)) != 0)
return (-1);
return (0);
}
static int
lm75_write(device_t dev, uint32_t addr, uint8_t *data, size_t len)
{
struct iic_msg msg[1] = {
{ addr, IIC_M_WR, len, data },
};
if (iicbus_transfer(dev, msg, nitems(msg)) != 0)
return (-1);
return (0);
}
static int
lm75_probe(device_t dev)
{
struct lm75_softc *sc;
sc = device_get_softc(dev);
sc->sc_hwtype = HWTYPE_LM75;
#ifdef FDT
if (!ofw_bus_is_compatible(dev, "national,lm75"))
return (ENXIO);
#endif
device_set_desc(dev, "LM75 temperature sensor");
return (BUS_PROBE_GENERIC);
}
static int
lm75_attach(device_t dev)
{
struct lm75_softc *sc;
sc = device_get_softc(dev);
sc->sc_dev = dev;
sc->sc_addr = iicbus_get_addr(dev);
sc->enum_hook.ich_func = lm75_start;
sc->enum_hook.ich_arg = dev;
/*
* We have to wait until interrupts are enabled. Usually I2C read
* and write only works when the interrupts are available.
*/
if (config_intrhook_establish(&sc->enum_hook) != 0)
return (ENOMEM);
return (0);
}
static int
lm75_type_detect(struct lm75_softc *sc)
{
int i, lm75a;
uint8_t buf8;
uint32_t conf;
/* Save the contents of the configuration register. */
if (lm75_conf_read(sc) != 0)
return (-1);
conf = sc->sc_conf;
/*
* Just write some pattern at configuration register so we can later
* verify. The test pattern should be pretty harmless.
*/
sc->sc_conf = LM75_TEST_PATTERN;
if (lm75_conf_write(sc) != 0)
return (-1);
/*
* Read the configuration register again and check for our test
* pattern.
*/
if (lm75_conf_read(sc) != 0)
return (-1);
if (sc->sc_conf != LM75_TEST_PATTERN)
return (-1);
/*
* Read from nonexistent registers (0x4 ~ 0x6).
* LM75A always return 0xff for nonexistent registers.
* LM75 will return the last read value - our test pattern written to
* configuration register.
*/
lm75a = 0;
for (i = 4; i <= 6; i++) {
if (lm75_read(sc->sc_dev, sc->sc_addr, i,
&buf8, sizeof(buf8)) < 0)
return (-1);
if (buf8 != LM75_TEST_PATTERN && buf8 != 0xff)
return (-1);
if (buf8 == 0xff)
lm75a++;
}
if (lm75a == 3)
sc->sc_hwtype = HWTYPE_LM75A;
/* Restore the configuration register. */
sc->sc_conf = conf;
if (lm75_conf_write(sc) != 0)
return (-1);
return (0);
}
static void
lm75_start(void *xdev)
{
device_t dev;
struct lm75_softc *sc;
struct sysctl_ctx_list *ctx;
struct sysctl_oid *tree_node;
struct sysctl_oid_list *tree;
dev = (device_t)xdev;
sc = device_get_softc(dev);
ctx = device_get_sysctl_ctx(dev);
tree_node = device_get_sysctl_tree(dev);
tree = SYSCTL_CHILDREN(tree_node);
config_intrhook_disestablish(&sc->enum_hook);
/*
* Detect the kind of chip we are attaching to.
* This may not work for LM75 clones.
*/
if (lm75_type_detect(sc) != 0) {
device_printf(dev, "cannot read from sensor.\n");
return;
}
if (sc->sc_hwtype == HWTYPE_LM75A)
device_printf(dev,
"LM75A type sensor detected (11bits resolution).\n");
/* Temperature. */
SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "temperature",
CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, dev, LM75_TEMP,
lm75_temp_sysctl, "IK", "Current temperature");
SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "thyst",
CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, dev, LM75_THYST,
lm75_temp_sysctl, "IK", "Hysteresis temperature");
SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "tos",
CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, dev, LM75_TOS,
lm75_temp_sysctl, "IK", "Overtemperature");
/* Configuration parameters. */
SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "faults",
CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_MPSAFE, dev, 0,
lm75_faults_sysctl, "IU", "LM75 fault queue");
SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "mode",
CTLFLAG_RW | CTLTYPE_STRING | CTLFLAG_MPSAFE, dev, 0,
lm75_mode_sysctl, "A", "LM75 mode");
SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "polarity",
CTLFLAG_RW | CTLTYPE_STRING | CTLFLAG_MPSAFE, dev, 0,
lm75_pol_sysctl, "A", "LM75 OS polarity");
SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "shutdown",
CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_MPSAFE, dev, 0,
lm75_shutdown_sysctl, "IU", "LM75 shutdown");
}
static int
lm75_conf_read(struct lm75_softc *sc)
{
uint8_t buf8;
if (lm75_read(sc->sc_dev, sc->sc_addr, LM75_CONF,
&buf8, sizeof(buf8)) < 0)
return (-1);
sc->sc_conf = (uint32_t)buf8;
return (0);
}
static int
lm75_conf_write(struct lm75_softc *sc)
{
uint8_t buf8[2];
buf8[0] = LM75_CONF;
buf8[1] = (uint8_t)sc->sc_conf & LM75_CONF_MASK;
if (lm75_write(sc->sc_dev, sc->sc_addr, buf8, sizeof(buf8)) < 0)
return (-1);
return (0);
}
static int
lm75_temp_read(struct lm75_softc *sc, uint8_t reg, int *temp)
{
uint8_t buf8[2];
uint16_t buf;
int neg, t;
if (lm75_read(sc->sc_dev, sc->sc_addr, reg, buf8, sizeof(buf8)) < 0)
return (-1);
buf = (uint16_t)((buf8[0] << 8) | (buf8[1] & 0xff));
/*
* LM75 has a 9 bit ADC with resolution of 0.5 C per bit.
* LM75A has an 11 bit ADC with resolution of 0.125 C per bit.
* Temperature is stored with two's complement.
*/
neg = 0;
if (buf & LM75_NEG_BIT) {
if (sc->sc_hwtype == HWTYPE_LM75A)
buf = ~(buf & LM75A_TEMP_MASK) + 1;
else
buf = ~(buf & LM75_TEMP_MASK) + 1;
neg = 1;
}
*temp = ((int16_t)buf >> 8) * 10;
t = 0;
if (sc->sc_hwtype == HWTYPE_LM75A) {
if (buf & LM75_0125C)
t += 125;
if (buf & LM75_0250C)
t += 250;
}
if (buf & LM75_0500C)
t += 500;
t /= 100;
*temp += t;
if (neg)
*temp = -(*temp);
*temp += TZ_ZEROC;
return (0);
}
static int
lm75_temp_write(struct lm75_softc *sc, uint8_t reg, int temp)
{
uint8_t buf8[3];
uint16_t buf;
temp = (temp - TZ_ZEROC) / 10;
if (temp > LM75_MAX_TEMP)
temp = LM75_MAX_TEMP;
if (temp < LM75_MIN_TEMP)
temp = LM75_MIN_TEMP;
buf = (uint16_t)temp;
buf <<= 8;
buf8[0] = reg;
buf8[1] = buf >> 8;
buf8[2] = buf & 0xff;
if (lm75_write(sc->sc_dev, sc->sc_addr, buf8, sizeof(buf8)) < 0)
return (-1);
return (0);
}
static int
lm75_str_mode(char *buf)
{
int len, rtrn;
rtrn = -1;
len = strlen(buf);
if (len > 2 && strncasecmp("interrupt", buf, len) == 0)
rtrn = 1;
else if (len > 2 && strncasecmp("comparator", buf, len) == 0)
rtrn = 0;
return (rtrn);
}
static int
lm75_str_pol(char *buf)
{
int len, rtrn;
rtrn = -1;
len = strlen(buf);
if (len > 1 && strncasecmp("high", buf, len) == 0)
rtrn = 1;
else if (len > 1 && strncasecmp("low", buf, len) == 0)
rtrn = 0;
else if (len > 8 && strncasecmp("active-high", buf, len) == 0)
rtrn = 1;
else if (len > 8 && strncasecmp("active-low", buf, len) == 0)
rtrn = 0;
return (rtrn);
}
static int
lm75_temp_sysctl(SYSCTL_HANDLER_ARGS)
{
device_t dev;
int error, temp;
struct lm75_softc *sc;
uint8_t reg;
dev = (device_t)arg1;
reg = (uint8_t)arg2;
sc = device_get_softc(dev);
if (lm75_temp_read(sc, reg, &temp) != 0)
return (EIO);
error = sysctl_handle_int(oidp, &temp, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
if (lm75_temp_write(sc, reg, temp) != 0)
return (EIO);
return (error);
}
static int
lm75_faults_sysctl(SYSCTL_HANDLER_ARGS)
{
device_t dev;
int lm75_faults[] = { 1, 2, 4, 6 };
int error, faults, i, newf, tmp;
struct lm75_softc *sc;
dev = (device_t)arg1;
sc = device_get_softc(dev);
tmp = (sc->sc_conf & LM75_CONF_FAULT) >> LM75_CONF_FSHIFT;
if (tmp >= nitems(lm75_faults))
tmp = nitems(lm75_faults) - 1;
faults = lm75_faults[tmp];
error = sysctl_handle_int(oidp, &faults, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
if (faults != lm75_faults[tmp]) {
newf = 0;
for (i = 0; i < nitems(lm75_faults); i++)
if (faults >= lm75_faults[i])
newf = i;
sc->sc_conf &= ~LM75_CONF_FAULT;
sc->sc_conf |= newf << LM75_CONF_FSHIFT;
if (lm75_conf_write(sc) != 0)
return (EIO);
}
return (error);
}
static int
lm75_mode_sysctl(SYSCTL_HANDLER_ARGS)
{
char buf[16];
device_t dev;
int error, mode, newm;
struct lm75_softc *sc;
dev = (device_t)arg1;
sc = device_get_softc(dev);
if (sc->sc_conf & LM75_CONF_MODE) {
mode = 1;
strlcpy(buf, "interrupt", sizeof(buf));
} else {
mode = 0;
strlcpy(buf, "comparator", sizeof(buf));
}
error = sysctl_handle_string(oidp, buf, sizeof(buf), req);
if (error != 0 || req->newptr == NULL)
return (error);
newm = lm75_str_mode(buf);
if (newm != -1 && mode != newm) {
sc->sc_conf &= ~LM75_CONF_MODE;
if (newm == 1)
sc->sc_conf |= LM75_CONF_MODE;
if (lm75_conf_write(sc) != 0)
return (EIO);
}
return (error);
}
static int
lm75_pol_sysctl(SYSCTL_HANDLER_ARGS)
{
char buf[16];
device_t dev;
int error, newp, pol;
struct lm75_softc *sc;
dev = (device_t)arg1;
sc = device_get_softc(dev);
if (sc->sc_conf & LM75_CONF_POL) {
pol = 1;
strlcpy(buf, "active-high", sizeof(buf));
} else {
pol = 0;
strlcpy(buf, "active-low", sizeof(buf));
}
error = sysctl_handle_string(oidp, buf, sizeof(buf), req);
if (error != 0 || req->newptr == NULL)
return (error);
newp = lm75_str_pol(buf);
if (newp != -1 && pol != newp) {
sc->sc_conf &= ~LM75_CONF_POL;
if (newp == 1)
sc->sc_conf |= LM75_CONF_POL;
if (lm75_conf_write(sc) != 0)
return (EIO);
}
return (error);
}
static int
lm75_shutdown_sysctl(SYSCTL_HANDLER_ARGS)
{
device_t dev;
int error, shutdown, tmp;
struct lm75_softc *sc;
dev = (device_t)arg1;
sc = device_get_softc(dev);
tmp = shutdown = (sc->sc_conf & LM75_CONF_SHUTD) ? 1 : 0;
error = sysctl_handle_int(oidp, &shutdown, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
if (shutdown != tmp) {
sc->sc_conf &= ~LM75_CONF_SHUTD;
if (shutdown)
sc->sc_conf |= LM75_CONF_SHUTD;
if (lm75_conf_write(sc) != 0)
return (EIO);
}
return (error);
}